A conventional GSM (Global System for Mobile Communications) or UMTS (Universal Mobile Telecommunications Service) core network provides bearer control and call control. The bearer control is the aspect of signaling related to the control of the selection of a path through the transmission network and utilizing (reserving, releasing and setting up) the required resources. The call control is the aspect of signaling related to the subscriber and service control, taking, e.g., the subscriber state into consideration.
In the existing implementations of N-ISDN (Integrated Services Digital Network) the call control and the bearer control are integral with one another. A user plane is associated directly with the control servers, such as MSCs (Mobile Services switching Centers) and GMSCs (Gateway MSCs). Thus, the control nodes implement both application logic for signaling and the user plane.
The present invention is directed to separation of the call control and the bearer control.